The present invention relates to a probe for testing electrical properties of test samples.
When performing resistance measurements for determining electrical properties of a test sample, a test probe comprising one or more arms each carrying a tip for establishing electrical contact to the test surface is brought into contact with the test surface.
The present invention provides a cantilever (beam) geometry that enables a non-penetrating static contact to be formed between a cantilever tip and a test sample surface. Further, the present invention provides a multi-cantilever probe with one or more cantilevers defined by the cantilever (beam) geometry. Still further the present invention provides a methodology for designing nanoelectromechanical systems (NEMS) and microelectromechanical systems (MEMS) for which a low wear static contact is desired to improve stability and lifetime of a mechanical contact or an electromechanical contact.
Microscopic four point probes are used as metrology tool for electrical characterisation of conductive and semi-conductive thin films and multi-layered structures. As illustrated in FIG. 1 it has been observed that mechanical movement (sliding and vibrations) in the contact between a surface and the tip of a straight cantilever causes wear of the cantilever tip. To reduce this mechanical wear and to reduce the tip penetration into a sample surface, a flexible cantilever has been designed to obtain a non-penetrating static mechanical contact upon surface contact.
Related systems and methods may be found in publications such as US 2004/072452, US 2003/102878, WO 2005/031376, U.S. Pat. No. 6,672,875, US 2001/012739, U.S. Pat. No. 4,383,217, EP 1 085 327, US 2004/183554, U.S. Pat. Nos. 6,943,571, 4,703,252, 5,691,648, 6,747,445, US 2005/0151552, US 2005/0081609 and US 2005/0062448. Reference is made to all of the above-mentioned US patent publications, all of which are hereby incorporated in the present specification by reference in their entirety for all purposes.